rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4899/1:b..l P5876/1:b..l P5290/1:b..l (detected by 1, t=10502 jiffies, g=18713, q=49 ncpus=2) task:udevd state:R running task stack:23720 pid:5290 ppid:3637 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696 RIP: 0010:lock_is_held_type+0x13a/0x190 kernel/locking/lockdep.c:5710 Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc90003907898 EFLAGS: 00000206 RAX: dda2a753711ee700 RBX: ffff8880297e8000 RCX: dda2a753711ee700 RDX: 0000000000000000 RSI: ffffffff8a8c1700 RDI: ffffffff8adef760 RBP: 0000000000000001 R08: 0000000000000004 R09: 0000000000000003 R10: fffffbfff2e0b09c R11: 1ffffffff2e0b09c R12: 0000000000000000 R13: 0000000000000246 R14: ffff888027d9ea58 R15: ffff8880297e8ae0 lock_is_held include/linux/lockdep.h:283 [inline] mt_locked lib/maple_tree.c:-1 [inline] mt_slot lib/maple_tree.c:814 [inline] mas_slot lib/maple_tree.c:847 [inline] mas_validate_parent_slot lib/maple_tree.c:7051 [inline] mt_validate+0xf7b/0x4c90 lib/maple_tree.c:7240 validate_mm_mt+0xcd/0x420 mm/mmap.c:295 validate_mm+0xcc/0x2b0 mm/mmap.c:332 do_mmap+0xc7/0xfd0 mm/mmap.c:1270 vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:520 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fa783f1d822 RSP: 002b:00007ffc08d0c048 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa783f1d822 RDX: 0000000000000003 RSI: 0000000000000400 RDI: 0000000000000000 RBP: 0000000000000022 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000400 R14: 00005595fa7ae0b0 R15: 0000000000000400 task:cmp state:R running task stack:24352 pid:5876 ppid:5833 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:mas_validate_gaps lib/maple_tree.c:6972 [inline] RIP: 0010:mt_validate+0x2a2a/0x4c90 lib/maple_tree.c:7244 Code: 24 38 eb 35 e8 47 44 7b f7 31 db 4c 3b a4 24 48 01 00 00 0f 83 35 0a 00 00 e8 32 44 7b f7 49 ff c4 49 ff c7 48 83 44 24 20 08 <4c> 89 64 24 40 49 bc 00 00 00 00 00 fc ff df 41 83 fe 03 48 89 5c RSP: 0018:ffffc90005597880 EFLAGS: 00000212 RAX: ffffffff8a05922e RBX: 0000000000000000 RCX: ffff888024590000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90005597a50 R08: ffff888024590000 R09: 0000000000000004 R10: 0000000000000003 R11: 0000000000000000 R12: 00007fff24bf9000 R13: ffffffff8bb15e81 R14: 0000000000000001 R15: 000000000000000e validate_mm_mt+0xcd/0x420 mm/mmap.c:295 validate_mm+0xcc/0x2b0 mm/mmap.c:332 do_mmap+0xc7/0xfd0 mm/mmap.c:1270 vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:520 ksys_mmap_pgoff+0x516/0x6f0 mm/mmap.c:1482 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f0be1584242 RSP: 002b:00007fff24ada4f8 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f0be12a2000 RCX: 00007f0be1584242 RDX: 0000000000000003 RSI: 0000000000002000 RDI: 00007f0be12a2000 RBP: 0000000000000812 R08: 0000000000000003 R09: 000000000000d000 R10: 0000000000000812 R11: 0000000000000206 R12: 00007fff24ada5b8 R13: 00007f0be1561580 R14: 00007fff24ada970 R15: 00000fffe495b4a2 task:syz-executor state:R running task stack:22656 pid:4899 ppid:4891 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6730 preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6754 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 unwind_next_frame+0x1892/0x20b0 arch/x86/kernel/unwind_orc.c:629 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122 save_stack+0xf3/0x1e0 mm/page_owner.c:127 __reset_page_owner+0x51/0x1a0 mm/page_owner.c:148 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384 free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3525 release_pages+0x1f92/0x2200 mm/swap.c:1035 __pagevec_release+0x6d/0xe0 mm/swap.c:1055 pagevec_release include/linux/pagevec.h:71 [inline] folio_batch_release include/linux/pagevec.h:135 [inline] shmem_undo_range+0x75b/0x2050 mm/shmem.c:946 shmem_truncate_range mm/shmem.c:1062 [inline] shmem_evict_inode+0x248/0xa40 mm/shmem.c:1171 evict+0x485/0x870 fs/inode.c:705 do_unlinkat+0x377/0x560 fs/namei.c:4405 __do_sys_unlink fs/namei.c:4446 [inline] __se_sys_unlink fs/namei.c:4444 [inline] __x64_sys_unlink+0x45/0x50 fs/namei.c:4444 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fdd5938e577 RSP: 002b:00007ffc87c77b08 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fdd5938e577 RDX: 00007ffc87c77b30 RSI: 00007ffc87c77bc0 RDI: 00007ffc87c77bc0 RBP: 00007ffc87c77bc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffc87c78c50 R13: 00007fdd59411d7d R14: 00000000000319a8 R15: 00007ffc87c78c90 rcu: rcu_preempt kthread starved for 10603 jiffies! g18713 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:28096 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_timeout+0x15c/0x280 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:742 Code: 48 89 df e8 b7 3b af f7 e9 4c ff ff ff e8 dd 07 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d 97 d4 64 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48 RSP: 0018:ffffc90000177de8 EFLAGS: 000002c6 RAX: 8a6c70305c570700 RBX: ffffffff8a21ce97 RCX: 8a6c70305c570700 RDX: 0000000000000001 RSI: ffffffff8a8c0580 RDI: ffffffff8adef760 RBP: ffffc90000177f20 R08: dffffc0000000000 R09: ffffed10171e6afa R10: ffffed10171e6afa R11: 1ffff110171e6af9 R12: 0000000000000001 R13: dffffc0000000000 R14: ffff88813fef9dc0 R15: 1ffffffff1c3ed96 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2fc23ffc CR3: 0000000064424000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: default_idle_call+0x84/0xc0 kernel/sched/idle.c:109 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1fc/0x570 kernel/sched/idle.c:303 cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:401 start_secondary+0xe4/0xf0 arch/x86/kernel/smpboot.c:281 secondary_startup_64_no_verify+0xcf/0xdb